We have established two permanent human cell lines that maintain the granulocytic characteristics of acute myelogenous leukemia (AML) and respond to the leukopoietic hormone colony-stimulating activity (CSA). These cell lines provide unique model systems for studying AML in man. These lines should also prove useful for the development of an antibody to human AML cells and for the study of the interaction of colony-stimulating activity with myeloid cells. The proposed investigations can provide framework for understanding the controls of cell differentiation and proliferation in acute myelogenous leukemia. The specific aim of this project is to investigate the modulation of cell proliferation and maturation in human myeloid leukemic cell lines. Secondary aims are (1) to elucidate the interaction of colony-stimulating activity on myeloid leukemic cells, (2) to establish new myeloid leukemia lines and to derive from the parent lines new clones with different biological characteristics, and (3) to develop and utilize a human acute myelogenous leukemia-associated antibody.